JP6760435B2 - Binder for printing ink, laminated ink composition for flexible packaging and printed matter - Google Patents

Description

The present invention relates to a binder for printing ink, a laminated ink composition for flexible packaging, and a printed matter.

In recent years, plastic films have come to be used in various fields as packaging materials. Printing on such a plastic film is performed by gravure printing or flexographic printing. With the diversification of packaging base materials, the performance required for printing inks and coating agents used for decoration or surface protection is becoming more and more sophisticated.

For example, printing inks for plastic films need to have excellent printability, adhesiveness, blocking resistance, gloss, and the like for a wide variety of films. Further, in the field of food packaging containers, hygienic laminated packaging containers are used in which the ink does not come into direct contact with the contents.

Generally, there are the following two methods for laminating. That is, an extrusion laminating method in which ink is printed using various plastic films as a printing base material and molten polyolefin or the like is laminated on the printed surface via an anchor coating agent, and a plastic film is laminated on the printed surface via an adhesive. It is a dry laminating method.

Therefore, the ink used in the laminating method must adhere well to a printing base material such as various plastic films, and must be excellent in adhesiveness to the laminated plastic film, printability, and laminating strength. Furthermore, for the purpose of sterilizing the contents, when the boil and retort treatment is performed by immersing the laminated packaging container in hot water, the boil and retort suitability does not cause laminate floating or wrinkles during the treatment. Is required.

Since most of the above ink performances mainly depend on the performance of the binder resin, various binder resins are used according to the required performance. Generally, a polyurethane resin is used as a binder resin for laminating ink (see Patent Documents 1 to 3).

Japanese Unexamined Patent Publication No. 2010-270215 Japanese Unexamined Patent Publication No. 2010-270216 Japanese Patent No. 4882206

Generally, as a binder resin for laminating ink, a polyurethane resin having an intramolecular urethane bond concentration as high as possible is used. However, when the urethane bond concentration is high, the boil / retort suitability of the ink tends to be poor, and methyl ethyl ketone is likely to deteriorate. The solubility in solvents such as ethyl acetate and isopropyl alcohol is reduced, and when these solvents are used, printing of the image area is caused by a phenomenon called plate clogging, in which solid ink is accumulated in the plate. There is a problem that defects occur (decrease in printability).

On the other hand, in inks using aromatic organic solvents such as toluene, the polyurethane resin skeleton is hardened to improve blocking resistance, and chlorinated PP (polypropylene) is added to improve boil / retort suitability and laminate strength. An ink with good printability, adhesiveness, and blocking resistance can be obtained. However, from the viewpoint of working environment and the like, the use of aromatic organic solvents and organic solvents that do not contain ketone organic solvents such as methyl ethyl ketone are being promoted (non-toluene, etc.). Further, with these polyurethane resins alone, it has been difficult for an ink obtained with an organic solvent containing no aromatic organic solvent to meet the demand for a wide variety of films.

An object of the present invention is to provide a binder for a printing ink for obtaining an ink having excellent printability, lamination strength and boil / retort property. Another object of the present invention is to provide a laminated ink composition for flexible packaging using a binder for printing ink and a printed matter thereof.

As a result of diligent research, the present inventors have conducted polyethylene glycol (hereinafter, "PEG") as a binder for printing ink of laminated ink for flexible packaging even when an organic solvent containing no aromatic organic solvent is used. It was found that it is effective to solve the problem by containing the polyurethane resin and the vinyl chloride vinyl acetate copolymer resin as components. The present invention has been completed based on such findings.

The present invention is a binder for printing ink containing a PEG-containing polyurethane resin and a vinyl chloride vinyl acetate copolymer resin as components, wherein the PEG-containing polyurethane resin is (A) a polyester polyol having a number average molecular weight of 1000 to 6000. It is obtained by reacting (B) PEG, (C) diisocyanate compound, and (D) chain extender, and the content ratio of (B) PEG is based on 100 parts by mass of PEG-containing polyurethane resin. The present invention relates to a binder for printing ink in the range of 1 to 40 parts by mass. By using the PEG-containing polyurethane resin and the vinyl chloride vinyl acetate copolymer resin as components, effects such as improvement in printability can be obtained. Further, when the content ratio of PEG is within the above range, effects such as improvement of boil / retort suitability and printability can be obtained.

The present invention also relates to the above-mentioned binder for printing ink, which has a number average molecular weight of (B) PEG of 200 to 4000. (B) When the number average molecular weight of PEG is within the above range, effects such as improvement of laminate strength can be obtained.

The present invention further relates to the above-mentioned binder for printing ink, in which a PEG-containing polyurethane resin is reacted with dimethylolpropionic acid. Further, by using a polyurethane resin containing dimethylolpropionic acid (hereinafter referred to as DMPA) as a component, effects such as improvement of laminate strength and improvement of boil / retort suitability can be obtained.

The present invention also relates to a laminated ink composition for flexible packaging containing the above-mentioned binder for printing ink, colorant and organic solvent as components.

The present invention also relates to the above-mentioned laminated ink composition for flexible packaging, wherein the organic solvent does not contain an aromatic organic solvent or a ketone organic solvent. The binder for printing ink of the present invention is particularly suitable for a laminated ink composition for flexible packaging that does not use an aromatic organic solvent or a ketone organic solvent, but an aromatic organic solvent or a ketone organic solvent is used. It can also be used in laminated ink compositions for flexible packaging, and exhibits excellent properties.

The present invention also relates to a printed matter obtained by printing the above-mentioned laminated ink composition for flexible packaging.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a binder for printing ink for obtaining an ink having excellent printability, laminate strength and boil / retort suitability.

Hereinafter, embodiments of the present invention will be described in detail.
The binder for printing ink of the present invention is a binder for printing ink containing a PEG-containing polyurethane resin and a vinyl chloride vinyl acetate copolymer resin as components, and the PEG-containing polyurethane resin has at least (A) a number average molecular weight of 1000 to 6000. It is obtained by reacting the polyester polyol, (B) PEG, (C) diisocyanate compound, and (D) chain extender, and the content ratio of (B) PEG is 100 mass of PEG-containing polyurethane resin. It is in the range of 1 to 40 parts by mass with respect to the part.

Examples of the diol component constituting the polyester polyol (A) used in the present invention include ethylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, triethylene glycol, 1- or 2-methyl. -1,3-butylene glycol, 1- or 2-methyl-1,4-pentylene glycol, 2,4-diethyl-1,5-pentanediol, tripropylene glycol, 1,2-propylene glycol, 1,3 -Butanjiol, 1-, 2- or 3-methyl-1,5-pentandiol, 2-methyl-1,3-propanediol, ethylene oxide of bisphenol A, propylene oxide, alkylene oxides such as ethylene propylene oxide Additives, neopentyl glycol, butyl ethyl propanediol and the like can be mentioned. Of these, particularly preferred are 3-methyl-1,5-pentanediol and neopentyl glycol.

The following polyfunctional polio can be used for a part of the diole component. Examples of the polyfunctional polyol include glycerin, trimethylolpropane, trimethyloluetan, 1,2,6-hexanetriol, 1,2,4-butantriol, sorbitol, pentaerythritol and the like. Be done.

Examples of the dicarboxylic acid constituting the polyester polyol include adipic acid, succinic acid, sebacic acid, azelaic acid, fumaric acid, maleic acid, terephthalic acid, isophthalic acid and the like, and a mixture of two or more thereof. Of these, particularly preferred are adipic acid and sebacic acid. Further, the anhydride of the dicarboxylic acid and the esterified product of a lower alcohol having 1 to 5 carbon atoms are also included.

The polyester polyol (A) in the present invention can be obtained by the same method as a conventionally known polyester production method. For example, the diol component and the dicarboxylic acid or acid anhydride are dehydrated and condensed to obtain a polyester polyol.

The polyester polyol (A) used in the present invention has a number average molecular weight of 1000 to 6000, and if the number average molecular weight is less than 1000, the urethane bond concentration in the molecule becomes high, the boil / retort suitability of the ink tends to be poor, and the methyl ethyl ketone Solubility in solvents such as ethyl acetate and isopropyl alcohol tends to decrease. On the other hand, when the number average molecular weight exceeds 6000, the urethane bond concentration in the molecule becomes low, and the adhesiveness, the laminate strength, and the blocking resistance tend to decrease. The number average molecular weight of the polyester polyol is preferably 1500 to 5000, and more preferably 2000 to 4000. The number average molecular weight can be measured by gel permeation chromatography (GPC) (converted to standard polystyrene).

The PEG (B) used in the present invention preferably has a number average molecular weight of 200 to 4000, more preferably 400 to 3000, and even more preferably 500 to 2000. When the number average molecular weight is 200 to 4000, effects such as improvement of laminate strength can be obtained.

It is in the range of 1 to 40 parts by mass, preferably 2 to 30 parts by mass, and more preferably 3 to 20 parts by mass with respect to 100 parts by mass of the PEG-containing polyurethane resin. (B) When the content ratio of PEG is in the range of 1 to 40 parts by mass, effects such as improvement of boil / retort suitability and printability can be obtained.

Examples of the (C) diisocyanate compound used in the present invention include alicyclic diisocyanates such as isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,4-cyclohexanediisocyanate, and methylcyclohexylene diisocyanate, tetramethylene diisocyanate, and hexamethylene diisocyanate. , Dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, aliphatic diisocyanate such as lysine diisocyanate, tolylene diisocyanate, xylylene diisocyanate, α, α, α', α'-tetramethylxylylene diisocyanate and other aromatics Examples thereof include aliphatic diisocyanates and modified versions of these diisocyanate compounds. These polyisocyanate compounds may be used alone or in combination of two or more. Of these, alicyclic diisocyanate is preferable, and isophorone diisocyanate (IPDI) is particularly preferable.

The PEG-containing polyurethane resin used in the present invention is preferably further reacted with a low molecular weight diol. As the low molecular weight diol, dimethylolpropionic acid (DMPA) is particularly preferable. The content of dimethylolpropionic acid (DMPA) is preferably in the range of 0.01 to 5 parts by mass, and more preferably 0.05 to 4 parts by mass with respect to 100 parts by mass of the PEG-containing polyurethane resin. , More preferably 0.1 to 3 parts by mass. By using dimethylolpropionic acid as a component, effects such as improvement of laminate strength and improvement of boil / retort suitability can be obtained.

As the (D) chain extender used in the present invention, various known ones can be used. For example, ethylenediamine, propylenediamine, hexamethylenediamine, triethylenetetramine, diethylenetriamine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, dimerdiamine and the like can be mentioned. Other molecules such as 2-hydroxyethylethylenediol, 2-hydroxyethylpropylenediol, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediol, 2-hydroxypropylethylenediamine, and di-2-hydroxypropylethylenediamine. Diamines having a hydroxyl group inside, neopentyl glycol, butylethylpropanediol, ethylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, triethylene glycol, 1- or 2-methyl -1,3-butylene glycol, 1- or 2-methyl-1,4-pentylene glycol, 2,4-diethyl-1,5-pentanediol, tripropylene glycol, diethylene glycol, 1,2-propylene glycol, 1 , 3-Butanjiol, 1-, 2- or 3-Methyl-1,5-pentandiol, 2-Methyl-1,3-Propanediol and other diols, ethylene oxide of bisphenol A, propylene oxide, ethylene Examples thereof include alkylene oxide adducts such as propylene oxide, and other diols. Of these, particularly preferred is isophorone diamine.

Examples of the chain extender other than the above include diols having a tertiary amine structure such as methyldiethanolamine, methyldiisopropanolamine, phenyldiisopropanolamine, 4-methylphenyldiisopropanolamine, and 4-methylphenyldiethanolamine, and two of these. More than one kind of mixture can be mentioned.

Further, in the present invention, a chain elongation terminator can be used as needed. Examples of the chain extension terminator include monoalcohols (methanol, propanol, butanol, 2-ethylhexanol, etc.), monoamines [monos with 2 to 8 carbon atoms or dialkylamines (butylamine, dibutylamine, etc.), monoamines with 2 to 6 carbon atoms. Alternatively, dialkanolamine (monoethanolamine, diethanolamine, propanolamine, isopropanolamine, etc.)] and the like can be mentioned.

The PEG-containing polyurethane resin used in the present invention is a conventionally known method, for example, JP-A-62-153366, JP-A-62-153637, JP-A-1-236289, JP-A-2-64173. It can be obtained by the method disclosed in Japanese Patent Application Laid-Open No. 2, JP2-64174, JP-A-2-64175 and the like.

Specifically, polypropylene glycol and the combined polyol and the diisocyanate compound are reacted at a ratio of an excess of isocyanate groups to obtain a prepolymer having terminal isocyanate groups, and the obtained prepolymer is placed in an appropriate solvent, that is, non-toluene. Ester solvents such as ethyl acetate, propyl acetate and butyl acetate commonly used as solvents for gravure inks; ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; methanol, ethanol, isopropyl alcohol, n-butanol and the like. Alcohol-based solvent; hydrocarbon-based solvent such as methylcyclohexane and ethylcyclohexane; or a two-step method of reacting with a chain extender and / or terminal blocker in a mixed solvent thereof, or polypropylene glycol and a combined polyol, diisocyanate. It is produced by a one-step method in which a compound, a chain extender and / or a terminal sequestering agent are reacted at once in a suitable solvent among the above.

The binder for printing ink of the present invention contains a PEG-containing polyurethane resin and a vinyl chloride vinyl acetate copolymer resin as components, and the composition thereof is vinyl chloride vinyl acetate copolymer resin / PEG-containing polyurethane resin = 1/2 in terms of mass ratio. It is preferably ~ 9. Within this range, effects such as improvement in printability can be obtained.

The vinyl chloride vinyl acetate copolymer resin having a hydroxyl group used in the present invention can be obtained by two kinds of methods. One is obtained by copolymerizing a vinyl chloride monomer, a vinyl acetate monomer and a vinyl alcohol in an appropriate ratio. The other is obtained by copolymerizing vinyl chloride and vinyl acetate and then partially saponifying the vinyl acetate. In the vinyl chloride vinyl acetate copolymer resin having a hydroxyl group, the properties of the resin film and the resin dissolution behavior are determined by the monomer ratio of vinyl chloride, vinyl acetate and vinyl alcohol. That is, vinyl chloride imparts toughness and hardness of the resin film, vinyl acetate imparts adhesiveness and flexibility, and vinyl alcohol imparts good solubility in polar solvents.

In the binder for printing ink of the present invention obtained as described above, a colorant, an organic solvent, and, if necessary, a surfactant, a wax, and other additives for improving the ink fluidity and the ink surface film are added. A laminated ink composition for flexible packaging (printing ink) can be produced by appropriately blending and kneading using a normal ink manufacturing apparatus such as a ball mill, an attritor, or a sand mill. The blending amount of the binder of the present invention in the flexible packaging laminate ink composition (printing ink) is 3 to 20% by mass in terms of the resin solid content in the flexible packaging laminate ink composition (printing ink). It is preferable to blend in.

The organic solvent used in the flexible packaging laminate ink composition (printing ink) preferably does not contain an aromatic organic solvent or a ketone organic solvent from the viewpoint of the usage environment, for example, methanol, ethanol, isopropanol, and the like. Examples thereof include alcohol solvents such as n-propanol and methoxypropanol, and ester solvents such as ethyl acetate, n-propyl acetate, isopropyl acetate and butyl acetate, which are used alone or as a mixture of two or more kinds.

The laminated ink composition for flexible packaging of the present invention is suitable as a printing ink for a plastic film as a packaging material, and printing on such a plastic film may be performed by gravure printing or flexo printing, which are generally performed. .. Then, for example, an extrusion laminating method in which ink (laminate ink composition for flexible packaging) is printed using various plastic films as a printing base material, and molten polyolefin or the like is laminated on the printed surface via an anchor coating agent, or the above-mentioned A printed matter is produced by performing a dry laminating method in which a plastic film is laminated on a printed surface via an adhesive.

Hereinafter, preferred examples of the present invention will be described, but the present invention is not limited to these examples. Hereinafter, "part" represents "parts by mass" and "%" represents "% by mass".

Synthesis Example 1 (Synthesis of Polyurethane Resin a)
In a round-bottomed flask equipped with a stirrer, a thermometer and a nitrogen gas introduction tube, 295 parts of a polyester polyol (3-methyl-1,5-pentanediol adipate) having a number average molecular weight of 3000 as a component (A), (B). Five parts of polyethylene glycol having a number average molecular weight of 400 and 49.3 parts of isophorone diisocyanate (IPDI) as a component were charged and reacted at 105 ° C. for 6 hours under a nitrogen stream to have an isocyanate group content of 2.67%. After producing the prepolymer, 233 parts of ethyl acetate was added to prepare a uniform solution of urethane prepolymer. Subsequently, 582 parts of the urethane prepolymer solution was added to a mixture consisting of 20 parts of isophorone diamine (IPDA), 1.7 parts of di-n-butylamine (DBA), 373 parts of ethyl acetate and 260 parts of isopropyl alcohol as the component (D). Then, the reaction was carried out at 60 ° C. for 3 hours. The polyurethane resin thus obtained (hereinafter, polyurethane resin a) had a resin solid content concentration of 30% by mass, a viscosity of 500 mPa · s (25 ° C.), and an amine value of 0.8 mgKOH / g.

(Synthesis Examples 2 to 13)
Using the raw materials shown in Tables 1 and 2, polyurethane resin solutions b to m were obtained in the same manner as in Synthesis Example 1.

(Examples 1 to 10 and Comparative Examples 1 to 3)
Regarding color pigment dispersibility, 28 parts of polyurethane resin of Synthesis Examples 1 to 13, 10 parts of vinyl chloride vinyl acetate copolymer resin (15% solution with ethyl acetate), 10 parts of cyanine blue, mixed solvent ethyl acetate / isopropyl A laminated ink composition for flexible packaging having a composition of 52 parts of alcohol = 7/3 (mass ratio) was dispersed for 3 hours using a pigment disperser (paint shaker), and then using a mixed solvent, Zahn Cup No. The viscosity was adjusted to 15 seconds in 3, and the following (1) color pigment dispersibility was evaluated for the flexible packaging laminate ink composition.

In addition, 35 parts of polyurethane resin of Synthesis Examples 1 to 13, 10 parts of vinyl chloride vinyl acetate copolymer resin (15% solution made with ethyl acetate), 35 parts of titanium white, mixed solvent ethyl acetate / isopropyl alcohol = 7/3. A laminated ink composition for flexible packaging having a composition of 20 parts (mass ratio) was dispersed for 1 hour using a pigment disperser (paint shaker), and the above mixed solvent was used to disperse Zahn Cup No. The viscosity was adjusted using the above solvent so that the time was 3 for 15 seconds, and the following (2) to (7) were evaluated and examined for the flexible packaging laminate ink composition. The above results are summarized in Tables 3-4.

(1) Color pigment dispersibility A polyethylene terephthalate film (abbreviated as PET film) is printed with the above-mentioned ink (cyanine blue) to prepare a printing film, and the state of the coating film on the printed matter is visually determined. did. The evaluation criteria are as follows.
"○": The coating film has no color unevenness and the pigment dispersion is good.
"△": The coating film has some color unevenness and the pigment dispersion is slightly inferior.
“X”: The coating film has uneven color and the pigment dispersion is inferior.

(2) Printability The state of the print pattern printed on PET film using the small gravure printing tester with the ink (titanium white) described above, that is, the state of the plate doctor running out, and the state of the print pattern related to cell clogging. The omission was judged by visual observation. The evaluation criteria are as follows.
"○": Good printability.
“△”… Printability is insufficient.
"X": Those with extremely poor printability.

(3) Dry (DL) Laminating Strength A dry laminating machine that uses a urethane adhesive on the ink surface of printed matter printed with the above ink (titanium white) on PET film or nylon film (abbreviated as NY film). After laminating a CPP (non-stretched polypropylene) film at 40 ° C. for 2 days, the sample was cut to a width of 15 mm on the 3rd day after laminating, and 180 ° peel strength was measured.

(4) Boil suitability test After applying an isocyanate-based adhesive to the ink surface of a printed matter printed with the ink (titanium white) described above on a PET film or nylon film (abbreviated as NY film), 60 μm by a dry laminating machine. The unstretched polyethylene film of No. 1 was laminated to obtain a laminated product. This laminated product was made into a bag, a water / oil mixture was placed therein, and the mixture was sealed and then heated in hot water at 95 ° C. for 30 minutes. The floating state of the laminated product was observed to evaluate the boil suitability.
"○": The laminated product has no floating.
"△": The laminated product is partially lifted.
"X": Floating on the entire surface of the laminated product.

(5) Retort Suitability Test After applying an isocyanate-based adhesive to the ink surface of a printed matter printed with the ink (titanium white) described above on a PET film or NY film, a 60 μm unstretched polypropylene film is applied by a dry laminating machine. Laminated to obtain a laminated product. This laminated product is made into a bag, a water / oil mixture is placed inside and sealed, and then heated in hot water at 120 ° C. for 30 minutes, and the floating state of the laminated product is observed to evaluate the retort suitability. did.
"○": The laminated product has no floating.
"△": The laminated product is partially lifted.
"X": Floating on the entire surface of the laminated product.

(6) Adhesive The PET film was printed with the ink (titanium white) described above to prepare a printing film. After leaving the printing film for 24 hours, a cellophane tape was attached to the printing surface, and the state of the coating film on the printing surface when the film was rapidly peeled off was observed and evaluated.
"○" ... 80% or more of the print film remains on the film.
"Δ" ... 50 to 80% of the print film remains on the film.
"X" ... 50% or less of the print film remains on the film.

(7) Blocking resistance A printing film was prepared by printing on a PET film using the ink (titanium white) described above. The printed surfaces of the printing films were overlapped and allowed to stand at 40 ° C. for 15 hours under a load of 4 × 10 ⁵ Pa, and then the adhesion state of the printed surfaces was observed.
"○": Adhesion of 0% to less than 20% of the contact area.
“Δ”: Adhesion of 20% or more to less than 50% of the contact area.
“X”: 50% or more of the contact area is adhered.

As shown in Tables 3 to 4, Comparative Examples 1 to 3 in which the content ratio of (B) PEG is not in the range of 1 to 40 parts by mass with respect to 100 parts by mass of the PEG-containing polyurethane resin are the color pigment dispersibility. It is inferior in printability, boilability, retort suitability, adhesiveness, and blocking resistance. On the other hand, in Examples 1 to 10 in which the content ratio of (B) PEG is in the range of 1 to 40 parts by mass with respect to 100 parts by mass of the PEG-containing polyurethane resin as a binder, the color pigment dispersibility , Printability, boil suitability, retort suitability, adhesiveness, and blocking resistance are all excellent. Therefore, the ink using the printing ink binder of the present invention has good color pigment dispersibility and excellent solubility in the solvent without using an aromatic organic solvent or a ketone organic solvent, so that the plate may be clogged. It is suppressed and printing defects in the image area do not occur. Further, the binder for printing ink of the present invention is excellent in printability and also excellent in boil and retort suitability, and is therefore extremely useful as a binder for printing ink used in food packaging containers and the like.

Claims (8)

A binder for solvent-based printing inks containing polyethylene glycol (hereinafter referred to as "PEG")-containing polyurethane resin and vinyl chloride vinyl acetate copolymer resin as components.
The PEG-containing polyurethane resin is obtained by reacting (A) a polyester polyol having a number average molecular weight of 1000 to 6000, (B) PEG, (C) a diisocyanate compound, and (D) a chain extender. Yes,
The content ratio of (B) PEG is in the range of 1 to 30 parts by mass with respect to 100 parts by mass of the PEG-containing polyurethane resin.
A binder for printing ink, wherein the content ratio of the vinyl chloride vinyl acetate copolymer resin / the PEG-containing polyurethane resin is 1/2 to 9 in terms of mass ratio. The binder for printing ink according to claim 1, wherein the number average molecular weight of (B) PEG is 200 to 4000. The binder for printing ink according to claim 1 or 2, wherein the PEG-containing polyurethane resin is obtained by reacting dimethylolpropionic acid. A laminated ink composition for flexible packaging containing the binder for printing ink according to any one of claims 1 to 3. The laminated ink composition for flexible packaging according to claim 4, further containing an organic solvent. The laminated ink composition for flexible packaging according to claim 5, wherein the organic solvent contains an alcohol solvent or an ester solvent. The laminated ink composition for flexible packaging according to claim 5 or 6, wherein the organic solvent does not contain an aromatic organic solvent or a ketone organic solvent. A printed matter obtained by printing the laminated ink composition for flexible packaging according to any one of claims 4 to 7.